MVHR commissioning

[BrianB]

Hi,

I'm doing a self build in Aberdeenshire and we're nearing our completion, where the budget is becoming stretched!

One of the things I need to do is to commissioning my MVHR system. I'm familiar with industrial ventilation systems, and balancing them, but I'm not sure what format the BC will need to look for in a domestic system. Does anyone have a copy of a domestic MVHR test format, or if anyone has a copy their test report carried out by a 3rd party?

[Jeremy Harris]

Welcome.

 

There are loads of threads here discussing it:

 

 

 

 

 

 

 

 

There are probably several more as well, so a further search should throw up more results.

[joe90]

I am about to balance mine (if I can pull my finger out) but my BCO only said “you have not got fans in the bathrooms and kitchen because you have MVHR”, he didn’t ask fir any figures. I think I remember members on here (must read old threads) saying they had rates below what building regs dictate and they are more than adequate.

[Bitpipe]

1 minute ago, joe90 said:

I am about to balance mine (if I can pull my finger out) but my BCO only said “you have not got fans in the bathrooms and kitchen because you have MVHR”, he didn’t ask fir any figures. I think I remember members on here (must read old threads) saying they had rates below what building regs dictate and they are more than adequate.

 

The approach many of us have taken is 

 

a) confirm that the min extract rates are being met for kitchens & bathrooms (n.b. we easily exceeded these without even trying)

b) balance in / out at a given air flow (the most fiddly bit)

c) figure out the fan speed required to meet the whole house ventilation requirement and confirm that your system can meet it. Then turn it back down to whatever you're comfortable with.

d) write up the above in a formal looking report and see if the BC ever asks for it.

 

Of the above, b) is probably the most important as it ensures the system is running well. a) should not be a challenge and c) is all down to personal preference. 

[ProDave]

If you read my thread above, I tried, and failed, to get the required ventilation rates for am MVHR system in Scotland.  So i set it up to the English requirements which are much more clearly specified.  It remains to be seem what BC actually want on completion.  If you succeed in finding any more information from Scottish BC please share with us.

[joe90]

Psssstttt, when I went for sign off I had a copy of @Jeremy Harris figures but with my name and address on it in case he asked for figures ?.

[Big Jimbo]

Joe90. Go straight to jail. Do not pass go, and do not collect £200. I once used structural calcs for a steel beam from one job for another. BC fella didn't even take them off me, just said he wanted to know i had some !

[joe90]

17 minutes ago, Big Jimbo said:

Joe90. Go straight to jail. Do not pass go, and do not collect £200. I once used structural calcs for a steel beam from one job for another. BC fella didn't even take them off me, just said he wanted to know i had some !

ha, you’ll be in the cell next to me ?????

[Oz07]

Interest collection of posts linked above cheers

[readiescards]

On 10/02/2020 at 15:49, Bitpipe said:

 

The approach many of us have taken is 

 

a) confirm that the min extract rates are being met for kitchens & bathrooms (n.b. we easily exceeded these without even trying)

b) balance in / out at a given air flow (the most fiddly bit)

c) figure out the fan speed required to meet the whole house ventilation requirement and confirm that your system can meet it. Then turn it back down to whatever you're comfortable with.

d) write up the above in a formal looking report and see if the BC ever asks for it.

 

Of the above, b) is probably the most important as it ensures the system is running well. a) should not be a challenge and c) is all down to personal preference. 

 

These 4 steps are exactly what I did!

 

At night I have the unit set to 3% to reduce the noise and open a window!